The receptor with high affinity for IgE (FcERI) is found exclusively on mast cells, basophils and related cells. Aggregation of IgE occupied FcERI by antigen triggers both the release of preformed mediators such as histamine and serotonin, as well as stimulating the synthesis of leukotrienes. It is the release of these mediators which result in the allergic condition. The most thoroughly characterized FcERI is that of the rat basophilic leukemia (RBL) cell line. It consists of three different subunits: (1) A 40-50 Kilodalton (Kd) glycoprotein alpha chain which contains the binding site for IgE, (2) A single 33 Kd beta chain and (3) Two 7-9 Kd disulfide linked gamma chains. The gene for human FcERI--has never been completely cloned and isolated. Only the gene coding for the alpha subunit of tat FcERI has been cloned and sequenced [see Kinet, et al., Biochemistry, 26:4605 (1987)]. The instant invention encompasses the cloning, sequencing and expression of the alpha subunit of the human FcERI.
The instant invention comprises a DNA sequence coding for the polypeptide corresponding to the alpha subunit of the human high affinity receptor for IgE (human FcERI).
The instant invention also comprises a polypeptide corresponding to the alpha subunit of human FcERI.
The instant invention also includes replicable prokaryotic or eukaryotic microbial expression vehicles capable of expressing the alpha subunit of the human FcERI polypeptide, transformed prokaryotic and eukaryotic microorganisms and cultures of these microorganisms which produce the alpha subunit of human FcERI polypeptide, as well as processes for producing the alpha subunit of the human FcERI polypeptide either through solid phase synthesis methods, or through the use of recombinant DNA technology in which the requisite gene sequences are inserted by means of a suitable DNA vector into a compatible prokaryotic or eukaryotic organism.